Joe Biden and Bernie Sanders will face off one-on-one at the next Democratic primary debate after new rules released from the party on Friday keeps Tulsi Gabbard from the stage.

The three are the only ones left standing after multiple candidates exited the race this week – Pete Buttigieg, Amy Klobuchar, Michael Bloomberg and Elizabeth Warren. All but Warren have endorsed Biden.

The debate marks the final stage of the primary process as the Democrats prepare to select their nominee to face President Donald Trump this fall.